The invention relates to a pipe connection arrangement for connecting two pipe ends, in particular two pipe ends arranged in an exhaust line of a combustion engine. The invention furthermore relates to an exhaust line of a combustion engine of a vehicle, in particular a commercial vehicle, having a pipe connection arrangement, and to a commercial vehicle having an exhaust line of this kind.
In a pipe connection arrangement in an exhaust flow of a combustion engine, there is a need particularly to take into account the thermal pipe expansion during operation, owing to which the end faces of the two pipe ends move towards one another. In addition to such axial movement, angular misalignment and axial offsets can also occur in the connection arrangement. In order to compensate for such position tolerances, there is a widely known practice of arranging the mutually associated pipe ends in axial alignment and spaced apart and to connect them with a connecting pipe arrangement which can be deformed and/or displaced during relative movements of the pipe ends. Widely known examples of such compensating connecting pipe arrangements are corrugated-tube compensators or elastomer compensators connected to each of the two pipe ends, especially silicone rubber compensators, or, alternatively, plug-type connections. Such connecting pipe arrangements, which connect in a leaktight manner, are generally less resistant to the high thermal stresses of the kind that occur in an exhaust line of a combustion engine than the pipes used, and therefore weak points can form, with the possibility of leaks.
EP 2 273 175 B1 discloses an arrangement for connecting two pipe ends, wherein the two pipe ends are spaced apart by an axial gap and are connected in a plug-type connection by a connecting pipe section, such that the connecting pipe section is inserted into both pipe end regions, making leaktight contact with the inside of the pipe ends by an axial end segment. A leaktight joint which is capable of thermal expansion and compensates position tolerances is thus created here for connecting pipe ends in an engine exhaust system. Here, the connecting pipe section is to be composed of an alloy that can be precipitation-hardened. Moreover, the outer surfaces of the connecting pipe section are to have a wear-resistant coating. A wear-resistant galvanized coating of this kind is furthermore known from EP 2 096 194 A2.
A similar structure with a wear-resistant coating on the outer surface of the connecting pipe is furthermore known from EP 2 154 408 B1.
DE 10 2010 045 986 A1 likewise discloses internal connecting pipe embodiments of this kind but also simultaneously discloses external connecting pipes, where the pipe ends rest against the inner walls of the connecting pipe in a broad, extensive contact joint. Here, the pipe ends can each have a raised spherical segment running round in a ring shape on the outer circumferential surface thereof, wherein the associated inner wall regions of the external connecting pipe have a correspondingly spherical configuration to create an extensive contact joint.
An external connecting pipe is also known from DE 1 49 11 70 A, which shows a flexible pipe connection and in which the cylindrical pipe ends are provided with what are termed spherical raised surfaces, which rest over an extended area on a correspondingly spherically configured inner surface of the connecting pipe.
The disadvantages with all these known pipe connection arrangements is that they are, in some cases, very expensive to produce and assemble and furthermore that position tolerances cannot be compensated to the desired extent.